TY - JOUR
T1 - Modeling Flow, Nutrient, and Sediment Delivery from a Large International Watershed Using a Field-Scale SWAT Model
AU - Dagnew, Awoke
AU - Scavia, Donald
AU - Wang, Yu Chen
AU - Muenich, Rebecca
AU - Long, Colleen
AU - Kalcic, Margaret
N1 - Publisher Copyright:
© 2019 American Water Resources Association
PY - 2019/10/1
Y1 - 2019/10/1
N2 - A large international watershed, the St. Clair-Detroit River System, containing both extensive urban and agricultural areas, was modeled using the Soil and Water Assessment Tool (SWAT) model. The watershed, located in southeastern Michigan, United States, and southwestern Ontario, Canada, encompasses the St. Clair, Clinton, Detroit (DT), Sydenham (SY), Upper, and Lower Thames subwatersheds. The SWAT input data and model resolution (i.e., hydrologic response units, HRUs), were established to mimic farm boundaries, the first time this has been done for a watershed of this size. The model was calibrated (2007–2015) and validated (2001–2006) with a mix of manual and automatic methods at six locations for flow and water quality at various time scales. The model was evaluated using Nash–Sutcliffe efficiency and percent bias and was used to explore major water quality issues. We showed the importance of allowing key parameters to vary among subwatersheds to improve goodness of fit, and the resulting parameters were consistent with subwatershed characteristics. Agricultural sources in the Thames and SY subwatersheds and point sources from DT subwatershed were major contributors of phosphorus. Spatial distribution of phosphorus yields at HRU and subbasin levels identified locations for potential management targeting for both point and nonpoint sources and revealed that in some subwatersheds nonpoint sources are dominated by urban sources.
AB - A large international watershed, the St. Clair-Detroit River System, containing both extensive urban and agricultural areas, was modeled using the Soil and Water Assessment Tool (SWAT) model. The watershed, located in southeastern Michigan, United States, and southwestern Ontario, Canada, encompasses the St. Clair, Clinton, Detroit (DT), Sydenham (SY), Upper, and Lower Thames subwatersheds. The SWAT input data and model resolution (i.e., hydrologic response units, HRUs), were established to mimic farm boundaries, the first time this has been done for a watershed of this size. The model was calibrated (2007–2015) and validated (2001–2006) with a mix of manual and automatic methods at six locations for flow and water quality at various time scales. The model was evaluated using Nash–Sutcliffe efficiency and percent bias and was used to explore major water quality issues. We showed the importance of allowing key parameters to vary among subwatersheds to improve goodness of fit, and the resulting parameters were consistent with subwatershed characteristics. Agricultural sources in the Thames and SY subwatersheds and point sources from DT subwatershed were major contributors of phosphorus. Spatial distribution of phosphorus yields at HRU and subbasin levels identified locations for potential management targeting for both point and nonpoint sources and revealed that in some subwatersheds nonpoint sources are dominated by urban sources.
KW - SWAT
KW - field-scale
KW - flow and water quality
KW - international watershed
KW - watershed modeling
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U2 - 10.1111/1752-1688.12779
DO - 10.1111/1752-1688.12779
M3 - Article
AN - SCOPUS:85073579744
SN - 1093-474X
VL - 55
SP - 1288
EP - 1305
JO - Journal of the American Water Resources Association
JF - Journal of the American Water Resources Association
IS - 5
ER -